21 years old, a second-year student in the swimming department of Haner Sports University. He can breathe in the water as freely as on land. He is a natural swimming genius who is unlucky.When he participated in his first international competition at the age of 17, he was disqualified due to a starting foul. From then on, he became panicked about starting.His views on the opposite sex are very clear, and he believes that women must be slim and beautiful.Later, his childhood savior Bok-joo appeared in front of him. Jun-hyung, who found school boring, often wanted to tease her.